What the lesson is about
I had not heard of "oobleck" until I started teaching in the US, writes Mary McCarney. But when I read the Dr Seuss book Bartholomew and the Oobleck with my first-grade class (P2), they asked, "Can we make oobleck?" We were exploring materials and their properties as part of our science unit, so this sounded like a good idea.
A little online research revealed that oobleck (a non-Newtonian fluid, similar to quicksand) can easily be whipped up with cornstarch and water. Adding food colouring for a more dramatic effect is optional (it stains little fingers). The final consistency should resemble thick yoghurt.
The children loved getting messy as they created, stirred, mixed and explored this fascinating new material - real hands-on science! It also provoked wonderful questions, as oobleck has the properties of both a solid and a liquid, but is neither. "How can it be runny, but then feel hard when you press down on it?" asked Sam.
His observations were accurate. If a force is applied, oobleck gets thicker. When at rest, it reverts to its fluid state. My pupils were able to roll up tight balls of oobleck in their fists. But as they opened their hands, it dripped through their fingers "like gooey gunk".
The children enjoyed the whole experience so much that they taught the kindergartners all about oobleck at our recent school science fair.
We found lots of entertaining YouTube videos showing how you can walk (or sink) in a pool of oobleck, and even make it dance on a stereo speaker.
Look out for a number of gooey recipes for messy lessons, shared by whitechica2. Or try Science Museum Learning's video and lesson plan about Newton's nemesis.